The present invention relates to an antiseptic compress for promoting the healing of infected wounds or wounds susceptible to infection, and to a dressing incorporating the antiseptic compress.
It is already known that dressings capable of maintaining a certain moisture level on the surface of a wound have a favorable action on the healing process. This property is utilized in numerous dressings, for example xe2x80x9cALGOPLAQUExe2x80x9d marketed by Laboratoires URGO or xe2x80x9cCOMFEELxe2x80x9d marketed by COLOPLAST, which use a dispersion of hydrocolloids in an adhesive hydrophobic matrix; in these dressings the hydrocolloid particles absorb the exudates and maintain a moist environment favorable to healing. However, in the case of highly exudative wounds, the absorption is inadequate and it is possible to observe an accumulation of fluids which are likely rapidly to become a focus of infection.
Another type of dressing, known as a tulle gras, uses greases and oils, such as officinal petrolatum and paraffin, to form a wound protection. Absorption of the exudates is not possible here and a compress has to be provided in the case of weeping wounds. In other cases the wound tends to dry and adhesions are then frequently observed between the dressing and the freshly regenerated tissues. This entails painful renewal of the dressing, if not destruction of the scar tissues. To avoid the problems of infection in wounds, it is known to add antiseptics to the dressing in order to limit or, preferably, reduce the development of infectious pathogens. Dressings are known in this field which contain antiseptics dispersed in an ointment based on hydrophobic fats, an example of such a dressing being UNITUL marketed by BAMA-GEVE. Also, EP-A-689425 discloses a hydrating gel comprising a hydrocolloid system based on alginate and sodium carboxymethyl cellulose and a preservative system consisting of antimicrobials and antifungals. Said gel is a hydrogel containing a high proportion of water (97%), in which the active agents are in solution. A similarly formulated dressing with the mark CONNETIVINA PLUS, marketed by FIDIA, is also known; this consists of a hydrogel based on polyethylene glycol and contains silver sulfadiazine in dispersion and a hyaluronic acid salt.
FR 2 775 903 is also known and describes an adhesive hydrocolloid mass for dressings, the absorption capacity of which is amplified and accelerated by the combined presence of a hydrocolloid and a surfactant. This adhesive mass can additionally contain an antiseptic, which can easily be diffused when the dressing has absorbed an aqueous fluid capable of partially dissolving said antiseptic.
In the case of dressings which have a hydrophobic contact layer based especially on fats or elastomers, it is much more difficult to obtain an antiseptic action by means of active substances dispersed in the contact layer. These active substances are trapped in the hydrophobic structure and therefore possess an extremely low bioavailability. This problem is exacerbated when using poorly absorbent or non-absorbent dressing structures comprising fairly cohesive elastomers in order to prevent the dressing structure from breaking down when the dressing is removed from the wound. For this reason there are no dressings at the present time which contain both synthetic elastomers and antiseptics in a non-adhesive and non-absorbent contact layer.
The aim of the present invention is to provide a non-adhesive and poorly absorbent contact compress for skin wounds or burns susceptible to infection, said compress being based on fats and hydrocolloids, and a dressing incorporating such a compress.
It has been found according to the invention that it is possible to obtain a compress consisting of a non-adhesive, amphiphilic, cohesive contact layer and having an antiseptic action. It has in fact been found that the bioavailability of the antiseptics dispersed in the contact layer can be considerably improved in the presence of a non-ionic surfactant with a hydrophilic/lipophilic balance (HLB) greater than 10.
The compress according to the invention, consisting of a cohesive structure based on synthetic elastomers of the tri-block type highly plasticized with a non-polar oil, is characterized in that it contains, in dispersion, a small amount of hydrocolloids, at least one antiseptic and at least one surfactant with a hydrophilic/lipophilic balance (HLB) greater than 10.
According to one particular feature of the invention, the synthetic elastomers are tri-block elastomers with a saturated central block, such as a copolymer of polystyrene blocks and polyethylene-butylene blocks (SEBS) or a copolymer of polystyrene blocks and polyethylene-propylene blocks (SEPS).
According to another particular feature of the invention, the non-polar oil is a paraffin oil, an officinal petrolatum or a mixture of these compounds.
According to another particular feature of the invention, the hydrocolloids are present in the form of sodium carboxymethyl cellulose (CMC).
According to another particular feature of the invention, the surfactant is of the non-ionic type and is selected from polyethoxylated derivatives of sorbitol fatty acid esters.
According to another particular feature of the invention, the antiseptics are antimicrobial active substances and/or antifungal active substances preferably selected from silver salts.
In a preferred embodiment of the invention, the wound-contacting layer is discontinuous and preferably consists of an open-mesh woven fabric totally coated with a non-adhesive cohesive gel so as to leave the meshes essentially unobstructed, said gel being formed of a highly plasticized, hydrophobic elastomeric matrix containing a dispersion of hydrocolloids, at least one antiseptic and at least one surfactant with a hydrophilic/lipophilic balance (HLB) greater than 10.